Miscellaneous Antibiotics

Question 1

Nitroimidazole Drugs

Answer 1

Metronidazole and Tinidazole

Question 2

Polymyxin Drugs

Answer 2

Polymyxin B and Polymyxin E (Colistin)

Question 3

RoA of Metronidazole

Answer 3

• Oral
• Rectal
• IV
• Gel

Question 4

Nitroimidazoles Spectrum

Answer 4

Broad:
→ anaerobic gram +ve
C. difficile
C. perfringens
→ Protozoa:
Ameba
Trichomonas vaginalis

Question 5

MoA of Nitroimidazoles

Answer 5

The Nitro group in the drug will be reduced inside MOs, this will form ROS in there, which will cause cell damage and eliminate the MOs

Question 6

A.D.M.E of Metronidazole

Answer 6

D: crosses BBB and achieves therapeutic conc. in the CNS

Question 7

Indications of Nitroimidazoles

Answer 7

1. Mixed intra-abdominal infections → C. difficile
2. Vaginitis → Trichomonas vaginalis
   - vaginal metronidazole gel is applied locally
3. Ampicillin-induced enterocolitis → C. difficile
4. Brain abscess

Question 8

Adverse Effects of Nitroimidazoles

Answer 8

• NVD, Stomatitis, Peripheral neuropathy
• Disulfiram-like reaction
  → it is the headache accompanied with consuming alcohol with nitroimidazoles
• Teratogenicity (in animals)
  → used with caution in pregnancy

Question 9

Properties of Tinidazole

Answer 9

• it is the 2nd generation of nitroimidazoles
• has less toxicity and mild side effects

Question 10

Properties of Polymyxins

Answer 10

• we have 5 polymyxins:
  A,B,C,D,E
• structure: Basic peptide
• source: Bacillus polymyxa
• reserved; used for MDR &
  nosocomial infections

Question 11

RoA of Polymyxin B

Answer 11

Eyedrop

Question 12

RoA of Polymyxin E (Colsitin)

Answer 12

• IV
• IM
• Inhalation

Question 13

Spectrum of Polymyxin

Answer 13

Narrow:
→ gram -ve
→ P. aeruginosa
→ Acinetobacter spp.

Question 14

MoA of Polymyxin E (Colistin)

Answer 14

Colistin is a cell membrane functions inhibitor, it works as a cationic detergent (disinfectant) to:
→ disturb bacterial cell membrane
→ inactivate endotoxins

Question 15

Indications of Polymyxin B

Answer 15

MDR Conjunctivitis

Question 16

Indications of Polymyxin E (Colistin)

Answer 16

1. MDR UTIs → P. aeruginosa on top of E. coli
2. MDR pneumonia → P. aeruginosa on top of S. pneumonia
3. Prophylaxis in patients undergoing ventilation and
   lung transplant